Atomic grape

I have six atomic grape plants. They were all sown in the same compost, at the same time, were potted on at the same time, and have been sat on the same windowsill. Three of the plants are the same height as most of my other tomato varieties and three are rather short. The three tall ones are all a similar height to each other, and the three short ones are also the same as each other. 

I really need to get rid of some of my tomato plants, but I'm rather tempted to grow all of these on, just to see what happens!